EMERGENCY services were bracing last night as storms with winds of up to 100km/h were forecast to lash the Hunter overnight.

Rainfall caused flash flooding and chaos on the roads yesterday, less than two weeks after record temperatures topped 45 degrees and bushfires came within metres of houses in the region.

Potentially dangerous storm-force winds forecast to smash the region’s coastline late yesterday were delayed six hours and predicted to arrive at 2am today.

Weatherwatch meteorologist Anthony Cornelius said the stronger winds had moved down from the north more slowly than expected.

‘‘The system slowed down a bit but the stronger wind gusts are expected to hit coastal areas overnight,’’ he said last night.

Since Friday night the State Emergency Service (SES) has received 177 jobs in the Hunter, with large numbers from Newcastle and Lake Macquarie. Most callouts were for leaking roofs and blocked drains.

Coastal suburbs suffered the worst of the rain, with the deluge including rainfall of 64millimetres in Merewether from 9am to 5pm.

Elsewhere Adamstown received 60 millimetres in the same period and Wallsend and Cooranbong, Lake Macquarie, had 62millimetres.

With many students returning to school tomorrow, many Hunter residents were returning home after holidays up and down the coast.

Emergency services were kept busy with scores of accidents, including a serious incident with a car and two motorcycles on Great North Road, Laguna, about 2pm.

Both male bikers were hospitalised, one with a fractured pelvis and another with a broken wrist, although it did not appear the injuries were life-threatening.

An accident involving at least two trucks near the Mooney Mooney Bridge closed all three northbound lanes of the F3 Freeway for about 30 minutes.

Heavy holiday traffic continued at Bulahdelah, Hexham and on the F3 Freeway, with queues reaching up to two kilometres.

Flooding blocked Industrial Drive at Mayfield and Bridges Road at Lambton for a few hours.

Police have called for motorists to stay vigilant and take care on roads today as heavy rain and strong winds are still on the cards.

The weather also affected flights at Newcastle’s Williamtown Airport.

Several flights, including arrivals and departures to Ballina, Brisbane and the Gold Coast, were cancelled due to safety concerns.

Numerous other trips were forced into delays of more than two hours.

Flooding has isolated thousands of NSW residents and caused evacuations in the state’s north, as Oswald beats a devastating path towards Sydney.

About 2000 people were cut off in the state’s drenched north yesterday afternoon, with about 850 people isolated at Ewingar, west of Lismore, and 400 at Darkwood, on the Bellinger River.

At 4.30pm flood warnings were in place for eight NSW river systems, the Bureau of Meteorology advised.

In Lismore, the NSW SES were doorknocking homes and 500 residents were being evacuated, with the Wilsons River at a height of 9.7metres, while in Grafton more than 1500 people are expected to be evacuated today as the Clarence River continues to rise.

At Bellingen, floods cut the town in half after a main bridge, Lavenders Bridge, went under water, with the Bellinger River tipped to reach 6.5metres yesterday.

Residents near the Tweed River, Wilsons and Richmond rivers and the Clarence Valley have been warned they could face major flooding.

Flood warnings are also in place for the Bellinger, Macleay, Hastings, Brunswick and Nambucca rivers.

By 2pm yesterday, the SES said it had received 1400 calls for help, mainly from the heavily affected northeast corner of NSW, with 13 flood rescues, including several involving people who had ignored warnings and tried to drive through flooding in the Tweed area.

A severe weather warning takes in major population centres including metropolitan Sydney and the Hunter Region, with the weather system expected to reach the Illawarra at dawn today.

Sydney and Newcastle were forecast to see the worst of it by late yesterday, with winds forecast to reach up to 100km/h and downpours